Many petrochemical facilities, such as refineries, involve the storage and handling of large quantities of combustible materials, such as hydrocarbon fluids. Hydrocarbon fluids are typically stored in large storage vessels and processed in a complex and interconnecting network of piping, pumps, heat exchangers, and reactor vessels at these facilities.
Fire protection at these facilities presents a difficult challenge. The labyrinth of interconnecting piping and equipment can limit the effectiveness of fixed water spray installations and restrict access of mobile fire fighting equipment. These problems are compounded by the large quantities of combustible materials at these facilities, requiring bulky fire fighting equipment capable of high flow rates of foam/water mixtures or other fire fighting fluids.
These problems have resulted in fire protection at these facilities being typically limited to perimeter protection provided by large capacity fixed or trailer mounted fire "monitors" (large swiveling fire nozzles) supplemented by smaller, more maneuverable vehicles. The smaller mobile equipment is useful for gaining access to small fires and for rescue operations, but smaller mobile equipment is not effective against a major fire. Instead, the fixed monitors are typically placed to provide perimeter protection, that is, placed to contain any fire within a perimeter around one portion of the facility. For example, a large hydrocarbon storage tank would be covered by foam or water streams from several monitors. If a fire in an adjacent portion of the facility erupted, the fixed fire monitors directed at the storage tank would prevent the fire from spreading across the perimeter and to the storage tank. This perimeter approach would essentially allow some fires to burn themselves out within the perimeter.
This type of fire protection exposes adjoining property and personnel to adverse impacts and added risks. Dense clouds of smoke can damage adjoining properties and harm personnel, as well as cause a traffic hazard and other problems. Burning embers and/or an explosion can carry the fire over any perimeter protection. For these and other reasons, it may be desirable to extinguish a major fire instead of providing perimeter protection.
However, in addition to access limitations, other limitations prevent large truck and trailer mounted monitors (capable of fighting a major fire) from performing well in refinery fire applications. Because a tank on a truck or trailer would be quickly depleted by the large flow rates of water required, the truck or trailer mounted monitors must typically be supplied by attached fire hoses. In relatively open areas, a fire truck may be positioned near a hydrant, the hoses attached, and the truck repositioned towards the fire (dragging out hose behind it). However, this type of activity can damage hoses in the restricted access of a refinery even if the truck itself can manage to gain access (e.g., by jockeying back and forth). Hose setup and hose hookup near a major fire, due to the time involved, can expose fire fighters to risk. In addition, the reaction force of the large quantities of discharged water from the fire monitors can further limit the design and mobility of a large capacity truck or trailer, e.g., time consuming filling of tanks must be accomplished prior to water discharge so that the vehicle does not tip over when discharging.